Gas turbine engines are widely utilized in fields such as power generation. A conventional gas turbine engine may include a compressor, a combustor, and a turbine. The compressor may supply compressed air to the combustor, where the compressed air may be mixed with fuel and burned to generate a working fluid. The working fluid may be supplied to the turbine, where energy may be extracted from the working fluid to produce work. The working fluid may exit the turbine via an exhaust section having a diffuser assembly.
At partial loads, the total pressure profile of the working fluid at the inlet of diffuser assembly is generally tip (i.e., outer wall) strong. A tip strong profile causes flow separation at the inner wall (i.e., hub side of the diffuser assembly). The skewed profile does not allow the working fluid to distribute evenly in the diffuser assembly, thus reducing the diffuser assembly performance. Moreover, skewed or non-uniform velocity profiles deteriorate the performance of the heat recovery steam generator (HRSG) assembly positioned downstream of the diffuser assembly, which leads to premature failure or damage of the HRSG assembly. Accordingly, there is a need to produce a substantially uniform velocity distribution of the working fluid within the exhaust flow path of the diffuser assembly, which in turn may be supplied to the HRSG assembly.